what type of ram older imacs use...


macrumors 6502
Feb 26, 2006
It always depends on the model....

G3 iMac started out with so-dimms (laptop memory) PC66, then went ot full size PC100/133 desktop RAM.

G4 iMac started with so-dimm user serviceable/accessible up to 512MB or full size desktop RAM internally, both PC133 then all the way to PC2100 & PC2700 DDR RAM.

So again, it depends on the model...


macrumors newbie
Aug 5, 2011
Salford, UK
On my G4 Quicksilver I used the Crucial.com system scanner to tell me, and then just to be double sure I checked on macupgrades.co.uk

I suggest if its the older PC133, or most of the slower bus SDRAM, you'll want to scout about on eBay for the modules as these are stupidly expensive in most online retailers now.